公开(公告)号：DE69730167T2

公开(公告)日：2005-08-04

申请号：DE69730167

申请日：1997-10-08

Applicant: ABB RESEARCH LTD

Inventor： JOHANSSON KENNETH ,  KOLS HAKAN

IPC: G01R15/14 ,  G01R31/12 ,  H02H7/04

公开(公告)号：AT272847T

公开(公告)日：2004-08-15

申请号：AT97909788

申请日：1997-10-08

Applicant: ABB RESEARCH LTD

Inventor： JOHANSSON KENNETH ,  KOLS HAKAN

IPC: G01R15/14 ,  G01R31/12 ,  H02H7/04

公开(公告)号：CA2248760A1

公开(公告)日：1997-09-18

申请号：CA2248760

申请日：1997-03-10

Applicant: ABB RESEARCH LTD

Inventor： KOLS HAKAN ,  BENGTSSON TORD ,  MARTINSSON LARS

IPC: H01F29/04 ,  G01R31/327 ,  G05F1/14 ,  G01R31/02

Abstract: A method for monitoring an on-load tap changer wherein the recording of sound and its conversion into a sound signal are initiated at the beginning of a connection operation of the tap changer and the sound signal is rectified, converted into a signal envelope, sampled digitally and continuously evaluated with respect to the condition of the tap changer by comparing the envelope with at least one fixed or one continuously updated reference envelope. The comparison is carried out selectively by calculating a dimensionless comparison figure Ti which is based on a quantity measure and a variation measure.

公开(公告)号：DE69730167D1

公开(公告)日：2004-09-09

申请号：DE69730167

申请日：1997-10-08

Applicant: ABB RESEARCH LTD

Inventor： JOHANSSON KENNETH ,  KOLS HAKAN

IPC: G01R15/14 ,  G01R31/12 ,  H02H7/04

公开(公告)号：CA2248760C

公开(公告)日：2003-06-03

申请号：CA2248760

申请日：1997-03-10

Applicant: ABB RESEARCH LTD

Inventor： MARTINSSON LARS ,  BENGTSSON TORD ,  KOLS HAKAN

IPC: H01F29/04 ,  G01R31/327 ,  G05F1/14 ,  G01R31/02

Abstract: A method for monitoring an on-load tap changer wherein the recording of soun d and its conversion into a sound signal are initiated at the beginning of a connection operation of the tap changer and the sound signal is rectified, converted into a signal envelope, sampled digitally and continuously evaluat ed with respect to the condition of the tap changer by comparing the envelope with at least one fixed or one continuously updated reference envelope. The comparison is carried out selectively by calculating a dimensionless comparison figure Ti which is based on a quantity measure and a variation measure.